Parameters

The duration to wait for a notification. The value DAT_TIMEOUT_INFINITE can be used to wait indefinitely.

evd_handle

Handle for an instance of EVD

Description

The dat_cno_wait() function allows the Consumer to wait for notification events from
a set of Event Dispatchers all from the same Interface Adapter. The
Consumer blocks until notified or the timeout period expires.

An Event Dispatcher that is disabled or in the "Waited" state does
not deliver notifications. A uDAPL Consumer waiting directly upon an Event Dispatcher
preempts the CNO.

The consumer can optionally specify a timeout, after which it is unblocked
even if there are no notification events. On a timeout, evd_handle is
explicitly set to a null handle.

The returned evd_handle is only a hint. Another Consumer can reap the
Event before this Consumer can get around to checking the Event Dispatcher.
Additionally, other Event Dispatchers feeding this CNO might have been notified. The
Consumer is responsible for ensuring that all EVDs feeding this CNO are polled
regardless of whether they are identified as the immediate cause of the
CNO unblocking.

All the waiters on the CNO, including the OS Wait Proxy Agent
if it is associated with the CNO, are unblocked with the NULL
handle returns for an unblocking EVD evd_handle when the IA instance is
destroyed or when all EVDs the CNO is associated with are freed.

Return Values

DAT_SUCCESS

The operation was successful.

DAT_INVALID_HANDLE

The cno_handle parameter is invalid.

DAT_QUEUE_EMPTY

The operation timed out without a notification.

DAT_INVALID_PARAMETER

One of the parameters was invalid or out of range, a combination of parameters was invalid, or the timeout parameter is invalid.